This is an ideology that, obviously, the conservatives espouse; however, please note that one must make a distinction here between political conservatism, and social (or cultural) conservatism—it is quite possible for a person adhere to one, but not the other—and our concern here is with the former. So, what then is political conservatism? Very briefly it is an ideology that advocates the preservation of the existing or a bygone political, social, and economic order. In other words it is an ideology that justifies maintenance of the status quo or its overthrow in favor of a past order (status quo ante) from the perspective of dominant power relations in society (in other words, it is an ideology that justifies an arrangement where those who are on top remain on top and those who are at the bottom remain at the bottom—from this perspective conservatism is inherently opposed to authentic democracy even while it may champion procedural democracy).
Historically, as an ideology, conservatism in the Western world arose in opposition to the revolutionary political, economic, and social changes wrought first by the French Revolution and later by the Industrial Revolution. For example, Edmund Burke, one of the prominent conservatives of the 18th century England, and whose thoughts would influence conservative political theory in the 19th century, believed in the preservation of the power of the monarchy and the landed gentry (the upper class); retention of a close relationship between the State and the Church; and the limitation of voting rights to a select few in society. Political conservatism in the twenty first century has tended to emphasize laissez-faire (meaning to “leave alone” in French) economics, where there is, supposedly, no State intervention in the economy—except in circumstances explicitly requiring the protection, hypocritically, of the interests of capitalists, of course—and virulent opposition to the development of a social safety net oriented State (usually referred to by conservatives as the "Welfare State"). Political conservatives, therefore, believe in absolute minimal government—except where capitalist interests are threatened (for example, conservatives do not object to the use of State power to smash trade unions—especially in situations of conflict between capitalists and workers).
Since conservatism harks back to a past social order it follows that present day conservatives (such as those in the United States), are opposed to many of the advances that have been made in the area of human and civil rights since the end of the Second World War, including rights for people of color, women, the working classes, and even children. They are also opposed to efforts by the federal government to regulate industries in order to protect consumers directly (e.g., from fraud, unsafe products, false advertising, etc.) and indirectly (e.g., from environmental pollution), and of course are vehemently opposed to almost any social safety net program designed to protect the less well-off from destitution. On the basis of their pronouncements, and on the basis of the foregoing, it can be safely asserted that in general (there will always be exceptions of course) conservatives—depending upon the degree of intensity of adherence to their ideology—tend to display the following attributes (listed here in no particular order): classism; racism; sexism; authoritarianism; intolerance toward alternative viewpoints, ideologies and lifestyle; patriarchal tendencies; unquestioning obedience to law—even if unjust; disdain for programs, projects and ideas aimed at protecting the environment because they believe environmental protection costs capitalists money (and since they have money they do not have to worry about their own health: e.g., if you can drink imported mineral water why worry about water pollution); disdain for the less well-off and those with disabilities (the former because they are considered lazy and the latter because they are considered a burden on society); and jingoism accompanied by much belligerency (since the wealthy tend to profit from war and usually their children are able to avoid military service). It is necessary to stress, however, that not all conservatives will share all of the attributes mentioned above; though all will share most of them. Notice too that from the perspective of capitalist democracies of the twenty first century, political conservatism is ultimately about the bourgeoisie waging class warfare on the working classes by means of neo-liberalism.
In a nutshell, then, true conservatives (excluding the ignorantsia--see note below) are those who believe in a political and economic order that would protect to the maximum possible privileges that they (or their allies) have garnered over the long course of human history at the expense of other human beings. (For an excellent account of the genesis of the conservative ideology see Moore [1966]). The sad truth, to put the matter differently, is that after one has cut through the thick jungle of pseudo-intellectualism, one is confronted with the incontrovertible fact that in every field of human endeavor (from the arts to the sciences), conservatism has stood as a reactionary bulwark against almost all human progress. That said, one can still champion a serious study of conservatism much in the same way that one would study, say, fascism. (See also Left/Right.)
Note: In the United States, in general, but not always, conservatives of today tend to be Republican Party members and/or usually vote for Republican candidates, and while in general they are wealthy or come from wealthy backgrounds, the party also attracts large sections of the Euro-American working classes or self-styled "middle classes" (meaning working classes with bourgeois pretensions). How does one explain the latter fact? The explanation for this irrational behavior is their deep ignorance--in the sense of their profound inability, due to their lack of political consciousness, to disentangle their subjective interests from their objective interests which then blinds them to the fact that the neo-liberal (and military-industrial complex-oriented) policies pursued by this party are so fundamentally opposed to their objective interests. Consider: the resolution or amelioration of the very socio-economic circumstances that creates a deep disenchantment among them with the economic and political status quo (that is, circumstances that are rooted in a politically-driven economically dysfunctional and unconscionable income inequality, coupled with a weak social safety net) cannot be possible by supporting a political party that champions and pursues policies that are responsible for these circumstances in the first place! What is more, to the extent that they are beneficiaries of policies pursued by the party they have ignorantly come to disdain (the Democratic Party), there is a profound inability to acknowledge their ignorance-based hypocrisy: benefiting from policies that their party of choice (the Republican Party) fundamentally opposes. [1] However, awareness of these facts requires possession of political consciousness!
Reminder: this definition concerns political conservatism, and not social conservatism. Social conservatism, for most people, is ultimately about subjective interests (even if they may not be aware of it because of the absence of political consciousness). However, one may concede here this fact: for a minority, the super-religious, social conservatism does represent objective interests.
[1]. The suggestion here is not that the Democratic Party is fundamentally any different from the Republican Party when it comes to taking care of the interests of the working classes (after all, it not only firmly believes in the essential soundness of capitalism as a cure-all for everything that ails humanity and the planet as a whole, but also champions and pursues policies that strengthen the military industrial complex). No, the suggestion here is that Democratic Party, from the perspective of the majority (that is, the working classes), constitutes, in a sufficiently meaningful way, the lesser of two evils. Ideally, there ought to exist a politically viable party of the working classes, by the working classes, and for the working classes (to paraphrase an oft-quoted line from that brief but poignant and majestic speech by President Abraham Lincoln, the Gettysburg Address). However, such a party can only come into existence if a significant section of the working classes acquired political consciousness. What about the Communist Party USA? Isn’t that a worker’s party? Yes, but it is too doctrinaire to be a viable political party (and to that extent it will always be a fringe party, especially in the face of the power and might of the two current dominant parties).